The present application is based on Japanese Priority Documents 2000-226409 filed on Jul. 27, 2000 and 2001-201551 filed on Jul. 3, 2001, the content of which is incorporated herein by reference.
1. Field of the Invention
This invention relates to a pipe joint acting as a hollow connecting segment for use in connecting a tube to a fluid inlet and a fluid outlet of a fluid device in the field of micro-machine and MEMS (Micro Electro Mechanical System, in particular, and its manufacturing method as well as the fluid device.
2. Discussion of the Background
At present, a miniature-sized machine called as a micro-machine or MEMS has been earnestly studied and developed in each of the nations in the world. Such a miniature-sized machine has been realized as a micro-machine (such as a motor or the like) under application of an ultra-fine machining technology for a semiconductor device and then gathered world""s attention at once. It is normally said that the miniature-sized machine represented by MEMS under utilization of a semiconductor process (such as an etching or a lithography) generally eliminates assembling work or adjustment process, whereby a system having some electronic circuits or sensors integrated therein can be realized on one substrate.
As an applied technology based on the aforesaid MEMS system, xcexc-TAS (Micro Total Analysis Systems) have been introduced for reduction in size of conventional large-scaled chemical analysis system and biochemical analysis system, and several developments have been reported on micro-fluid devices such as various kinds of micro-valves, micro-pumps, reaction channels and separation columns. In addition, the MEMS technology has been applied not only to the aforesaid analysis system but also to reduction in size of the chemical reactor realizing a chemical reaction or bio-chemical synthesis, resulting in that application of the MEMS technology to the fluid device has been remarkably expanded and activated.
The usual type of fluid device is constructed such that it has a fluid inlet for use in feeding fluid into the device and a fluid outlet for use in discharging fluid out of the device, some tubes are connected to the fluid inlet and the fluid outlet and the fluid is supplied to or discharged from the tube. Due to this fact, the fluid inlet and the fluid outlet require some joints (hollow projections) to which the tubes can be connected.
The present technology on a semiconductor (MEMS) is still yet restricted in a two-dimensional region and it is quite difficult to make a sufficient hollow projection for connecting a tube. Due to this fact, the conventional type of fluid device is presently constructed such that a commercially available joint (a coupling) is adhered to a hole formed at a lid member of the fluid device with adhesive agent to form the fluid inlet and the fluid outlet.
That is, the micro-fluid device reported up to now has been mainly developed for its major segment and a quite less number of reports about the inlet and the outlet have been found. Although the fluid device by itself is manufactured by MEMS technology as well as an ultra fining machining technology and a coupling technology mainly for glass (also including quartz) and a monolithic silicon (Si), the inlet and the outlet are constructed such that the commercially available joint is connected to the holes of the fluid device (the inlet and the outlet) with adhesive agent.
Referring now to FIGS. 39 and 40, the prior art fluid device will be described in brief. The device illustrated herein is a micro-reaction chamber 200 having a quite simple structure. A base 201 is comprised of a monolithic silicon, wherein a flow passage 202 and a reaction chamber 203 as shown are formed like a recess by etching work. A lid 204 is made of glass, and holes 205 which open in its front and rear direction are formed to be positioned at the end portions of each of the flow passages 202 of the base 201. In addition, joints 206 made of commercially available synthetic resin or metal are adhered to the holes 205 by adhesive agent 207. The lid 204 and the base 201 are adhered to each other by an anode connection not using any adhesive agent to complete the micro-reaction chamber 200.
In general, in the case of anodic coupling between silicon and glass, its substrate temperature is required to show several hundred xc2x0 C., so that the joints 206 are adhered after connection between the lid 204 and the base 201 in view of heat-resistant temperature of the adhesive agent 207 or the joint material. The joints 206 may become the fluid inlets 206a, 206b and the fluid outlet 206c, wherein the fluids A and B are introduced to the reaction chamber 203 through each of the fluid inlets 206a, 206b, reacted to each other in the reaction chamber 203, thereafter the reacted fluid becomes fluid C and the fluid C is discharged out of the outlet 206c. 
A general type of fluid device manufactured by MEMS process is constituted by silicon and glass (also including SiO2, quartz) where adhesive-less connection (fluoric acid connecting, anodic connecting and direct connecting) can be carried out. It is because, in the case of applying adhesive agent, there occurs a possibility that a reactor, a mixer, a flow passage and a valve or the like formed in small-size by MEMS process may become inferior due to squeezing-out of the adhesive agent or a permanent reliability at the connecting part with the adhesive agent is not excellent (leakage of fluid). As described above, irrespective of the fact that the device part is assembled by adhesive-less connection, the method for adhering the commercially available joint 206 with adhesive agent 207 is applied for inlets and outlets of many types of fluid device.
Some problems found in the prior art will be described as follows.
Since the commercially available joint is quite large in size as compared with that of the fluid device manufactured in quite small size using the semiconductor technology, the size of the device itself is made large only for adhering the joint to the device irrespective of the fact that the device can be made originally small in size. In addition, there are many problems such as closing of the hole under application of the adhesive agent, a connecting strength of the joint, contamination of fluid, a problem of heat-resistance and deterioration of easiness in manufacturing or the like. Such a present situation is a major cause not capable of attaining a high merit of making ultra fine formation or miniature-sized structure which is the major feature of the semiconductor (MEMS) technology and a reduction in manufacturing cost in batch process [a total assembling can be carried out in a unit of wafer (several hundred pieces and several thousand pieces)].
That is, as long as the conventional commercially available joint is used, the sizes of the inlet and outlet are not reduced even if the fluid device is set to have a miniature-size (micro-formation), so that a certain limitation may occur in a miniature-sized device. In addition, the connecting process using adhesive agent may cause the hole of the device to be clogged (squeezing-out of adhesive agent) and this is not a preferable one in view of reliability (in particular, reliability in shielding of fluid and leakage of fluid out of shield part). Further, adhesive agent may produce contamination of fluid in the fluid device (in particular, this is a severe problem in the analysis system). Additionally, there occurs a problem that the adhesive agent restricts limitation of fluid device against heat-resistance and anti-chemical product.
Due to this fact, in the field of the fluid device manufactured under application of the semiconductor (MEMS) technology in particular, it is desired to realize a method for forming the inlet and outlet directly in the hole of the fluid device, a quite small joint (a micro-fluid joint), a joint capable of coupling without applying any adhesive agent, a joint structure adapted for a batch process and its manufacturing method.
It is an object of the present invention to provide a pipe joint having a joint structure capable of connecting operation without applying any adhesive agent, its manufacturing method and a fluid device using the same.
These and further objects of the present invention are achieved by the novel pipe joint, method for manufacturing the same, and fluid device of the present invention.
According to the novel pipe joint of the present invention, a hollow layer-form projection is made to communicate with the hole and integrally fixed to the substrate having the hole. The projection is made such that a resin is filled in the hole to form a resin die projected out of the surface of the substrate and a layer-form member is integrally formed on the surface of the substrate and the side surfaces of the resin die, thereafter resin is removed.
According to the novel method for manufacturing a pipe joint of the present invention, the pipe joint is manufactured such that a resin is filled in the hole passed through the substrate and opened at its surface to form a resin die projected out of the surface of the substrate and the layer-form member is integrally formed at the surface of the substrate and the side surface of the resin die, thereafter the resin is removed.
According to the novel fluid device of the present invention, a fluid inlet and a fluid outlet communicating with the external area are arranged at a lid member with respect to a fluid function part closed by an enclosing element comprised of the lid member and a base. At lease one of the fluid inlet and the fluid outlet is formed by a pipe joint which communicates with the hole and in which a hollow layer-form projection is integrally fixed with respect to the substrate having a hole. The pipe joint is made by filling resin in the hole to form a resin die projected out of the surface of the substrate and after integrally forming a layer-form member at the surface of the substrate and the side surfaces of the resin die by a plating process, thereafter removing the resin.